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To create the solution, 11.6 g NaCl is placed in a volumetric flask, dissolved in some water, then followed by the addition of more water until the total volume reaches 100 mL. The density of water is approximately 1000 g/L and its molar mass is 18.02 g/mol (or 1/18.02 = 0.055 mol/g). Therefore, the molar concentration of water is
When one mole of water is added to a large volume of water at 25 °C, the volume increases by 18 cm 3. The molar volume of pure water would thus be reported as 18 cm 3 mol −1. However, addition of one mole of water to a large volume of pure ethanol results in an increase in volume of only 14 cm 3. The reason that the increase is different is ...
Since many measurement techniques in biology, chemistry, and physics are not sensitive enough to observe single molecules, single-molecule fluorescence techniques (that have emerged since the 1990s for probing various processes on the level of individual molecules) caused a lot of excitement, since these supplied many new details on the ...
The volume of such a mixture is slightly less than the sum of the volumes of the components. Thus, by the above definition, the term "40% alcohol by volume" refers to a mixture of 40 volume units of ethanol with enough water to make a final volume of 100 units, rather than a mixture of 40 units of ethanol with 60 units of water.
Raoult's law (/ ˈ r ɑː uː l z / law) is a relation of physical chemistry, with implications in thermodynamics.Proposed by French chemist François-Marie Raoult in 1887, [1] [2] it states that the partial pressure of each component of an ideal mixture of liquids is equal to the vapor pressure of the pure component (liquid or solid) multiplied by its mole fraction in the mixture.
It is one way of expressing the composition of a mixture in a dimensionless size; mole fraction (percentage by moles, mol%) and volume fraction (percentage by volume, vol%) are others. When the prevalences of interest are those of individual chemical elements , rather than of compounds or other substances, the term mass fraction can also refer ...
In such cases, the system can be treated as a mixture of the acid or base and water, which is an amphoteric substance. By accounting for the self-ionization of water, the true pH of the solution can be calculated. For example, a 5×10 −8 M solution of HCl would have a pH of 6.89 when treated as a mixture of HCl and water. The self-ionization ...
They can absorb water and other species with a critical diameter less than 4 Å such as NH 3, H 2 S, SO 2, CO 2, C 2 H 5 OH, C 2 H 6, and C 2 H 4. Bottle of 4A molecular sieves Some molecular sieves are used to assist detergents as they can produce demineralized water through calcium ion exchange, remove and prevent the deposition of dirt.